This invention is in the field of mercury cadmium telluride (HgCdTe) crystal growth. HgCdTe crystals currently are finding use in imaging detectors for infrared radiation. Various methods are known whereby these crystals may be produced and include: solid state recrystalliation, liquid phase epitaxy, elemental vapor phase transport, encapsulated close-spaced diffusion, and organo-metallic vapor phase epitaxy (OMVPE). In all cases sufficient mercury vapor must be maintained so as to prevent the dissociation of the ternary alloy. The existing OMVPE method is essentially one where within an open-flow glass reactor, a stream of mixed alkyls (such as dimethyl cadmium and diethyl tellurium) is pyrolytically dissociated in an atmosphere of elemental mercury vapor; and subsequently the CdHgTe alloy is deposited on a heated single crystal substrate of CdTe. The mercury vapor atmosphere is generated by heating elemental mercury in a reservoir with a hot plate, heating mantle or custom built oven. The substrate is placed on a susceptor pedestal made of carbon for example, and heated by R.F. induction. The system therefore has requirements for two separate heat sources . . . one to generate mercury vapor from a reservoir and a second to heat the susceptor/substrate by R.F. means. Each source must be separately controlled for two different required temperatures. A single heat source for both purposes would be desirable. Mercury vapor tends to condense quickly near the closest cool area, unless a hot walled reactor is used. On the other hand, metal alkyls will prematurely decompose in a hot walled reactor; thus the requirements for R.F. heating, where only the substrate/susceptor gets hot. The two heated conditions obviously work against each other for the required task. The present invention is a new OMVPE method which addresses the problems of multiple heat sources, hot walled reactor requirements and premature alkyl cracking.